The email you received is not from a mailing list. It was generated from one of the Community Forums in a Worldwide Waypoints mobile app. You get these notifications if you have a post in a forum and someone adds a post.
To stop receiving these notifications you need to do one of the following.
1. Open the app, go to the Community Forum with your post, tap your post and then tap the trash can to delete the post (or the trash cans to delete all your posts anywhere in the app).
2. Go to the “Community Forum Tools” screen and tap the “Delete All My Posts” button.
3. Go to the “Profile” screen, tap the “Edit” button and remove the check-mark from the “Public” box. Then tap the “Save” button.
4. From the “Profile” screen, tap the up arrow in the lower right corner to expose the buttons. Tap the “Delete My Account” button and confirm account deletion.
5. Finally, if you are super lazy, click this delete link to fill out a request to have Livio delete your account.
Thanx
Livio